In 2004, the Pfister Sisters will mark their 25th anniversary by looking back while looking forward, same as always.

As implied by its title, the Pfister Sisters’ new "Change in the Weather" CD reflects a season of change. It is the vocal trio’s first recording with Debbie Davis, who joined founders Holley Bendtsen and Yvette Voelker Cuccia four years ago. "Change" is also the first of the three Pfister CDs produced by the Sisters themselves, and the first released on their own label, Mambo Goddess Records.

But once again, their underlying motivation is to celebrate the Boswell Sisters. The three Boswell girls grew up in New Orleans early in the 20th century, absorbing the same varied African and European influences as pioneering jazz instrumentalists. They formed a vocal trio and moved first to the West Coast, then New York. Featured on a national radio show, they helped usher in the swing era, enjoying widespread acclaim until two of the sisters married and the group dissolved in the 1930s. But they left a lasting impression on scores of singers, most notably the Andrew Sisters, of "Boogie Woogie Bugle Boy" fame, and Ella Fitzgerald.

"The Boswells were so influential on American music and so successful that nobody realizes that they are indigenous to New Orleans, " Bendtsen said. "The whole jazz vocal group thing was started by two groups: The Boswell Sisters and the Mills Brothers. And the Boswells recorded first, in 1925, right along with Jelly Roll Morton and Louis Armstrong."

The Pfister Sisters’ previous release, "All’s Well That’s Boswell, " consisted entirely of Boswell Sisters material. This time, they expanded their repertoire to include other pre-World War II favorites influenced by the Boswells. In addition to "Boogie Woogie Bugle Boy, " the Pfisters recorded the Andrews Sisters’ first big hit, "Bei Mir Bist Du Schon, " which bore more than a trace of the Boswells’ frenetic swing.

"We wanted to show the larger influence, " Cuccia said, "that the Boswells had on jazz."

Bendtsen, a newly converted Boswells fan, first assembled the Pfister Sisters in 1979 for a gig with the New Leviathan Oriental Foxtrot Orchestra; the New Leviathan’s leader, George Schmidt, concocted the Pfister name. They reprised their collaboration at Jazzfest, and have continued on.

The Sisters’ future was uncertain after original member Suzi Malone moved to Maine in 1999. But Bendtsen and Cuccia recruited Davis to fill the vacancy. Davis then enlisted her husband, bassist Matt Perrine, to write horn charts for the group.

"He went back and did charts for things we had already recorded, and improved the hell out of them, " Bendtsen said. "He got eight or nine of them so tight by listening to the old ‘30s arrangements and redoing them. We re-recorded ‘It Don’t Mean a Thing (If It Ain’t Got That Swing)’ just to get his nice chart in."

A solid supporting cast backs the singers on "Change in the Weather, " including longtime collaborator Amasa Miller on piano, Jim Markway on bass, Jimmy Ballero on guitar, Gerald French on drums, Charlie Miller on trumpet, Rick Trolsen on trombone and Ken "Snakebite" Jacobs on saxophone, with Hector Gallardo guesting on percussion. All but Gallardo are slated to back the Pfister Sisters tonight at Snug Harbor.

"We’re so proud to have these musicians work with us, " Cuccia said. "They’re the working-class musicians of New Orleans -- they’re not famous, but they’re all so good and they’re all out there making their livings in a zillion different bands."

Intricate three-part harmonies are at the heart of the Pfisters’ swing, but the band’s contributions put a Big Easy spin on the sound and bring the arrangements to life, as evidenced by Miller’s tour de force trumpet solo in "L’aissez Faire."

"It’s not easy music to do, " Cuccia said. "It takes a willingness to work and rehearse. It’s hard to find that, particularly in a city where everybody jams and is very good at fitting in with whatever is going on in the moment. It becomes easy to say, ‘We don’t need to rehearse, let’s just go with it.’ You get a lot of wonderful stuff that way, but this particular music needs to be worked on."

"Change In the Weather" opens with "It’s the Girl, " a typically challenging Boswell number. Tempo changes fly out of nowhere, and the singers stretch and hold notes in unison, then unleash a lickety-spilt run. Cole Porter’s "Why Can’t You Behave" is restructured to accommodate three-part harmonies. The recordings of "There’ll Be Some Changes Made, " "Between the Devil and the Deep Blue Sea" and "You Oughta Be In Pictures" are based on Boswell arrangements. Gallardo refits Glenn Miller’s "Moonlight Serenade" with a subversive bolero rhythm. The Pfisters cooked up their own arrangement of Louis Prima’s "Sing Sing Sing, " with a horn chart by Charlie Miller.

"L’aissez Faire, " the album’s lone original composition, is a collaboration between Bendtsen, Amasa Miller and Phil Parnell. The lyrics describe the "mambo goddess" that is the namesake of the group’s label.

"That’s my name for New Orleans, " Bendtsen said. "To me, the mambo goddess has a basket on her head, walking through the French Quarter with a certain beat. That beat is in ‘L’aissez Faire.’ "

"We’d been doing it as a throwaway for 20 years, and we’d never actually spent any time trying to make it tight, " Bendtsen said. "When we heard our first take of it, we realized, ‘This isn’t sounding right.’ Finally by the end, it’s a smoking cut."